Author(s): Sanne Muis; Martin Verlaan; Hessel Winsemius; Jeroen C. J. H. Aerts; Philip J. Ward
Linked Author(s):
Keywords: Global modeling; Sea level extremes; Flood risk; Flexible mesh; Surges
Abstract: Coastal livelihoods and local economies are threatened by increasing coastal flood risk driven by climate change and socio-economic development. While the effective allocation of global adaptation efforts requires detailed information on risk trends, few studies assess coastal flood risk on a global-scale. Furthermore, the datasets that are currently being used for global risk assessment have great limitations for assessment of low-probability floods on a fully global scale or when time-series are required for the analysis. We address these issues by developing the first global hindcast of sea levels in all coastal areas. We simulate sea levels by forcing a global hydrodynamic model with the tidal potential and meteorological fields from ERA-Interim climate reanalysis (1979-2014) .A comparison between the modeled sea levels and observed sea levels for the year 2007 shows that, while some issues will need to be resolved to adequately represent tides in all coastal areas, the global model is able to reproduce the main characteristics of surge levels. Based on these first insights, we are convinced that we can obtain a reliable global hindcast of extreme sea levels by hydrodynamic modeling. Subsequently, exceedance probabilities of extreme sea levels can be estimated using extreme value statistics. We believe this approach may lead to a great improvement of the data available to assess coastal flood risk on a globalscale.
Year: 2015